Multilanguage: linkedin api does not support it?

You are, unfortunately, correct. LinkedIn is very US/English-centric right now. For the backend PHP communication, there is a little support for a 'few' other languages than English (don't have them off-hand), but it's nothing like what we've seen/you may be used to with Facebook.

There are many questions about this in their support area, and answers (from much earlier this year) have said that they're hoping to have multi-lingual support out by the end of this year. We haven't seen any movement in this direction, but are definitely keeping an eye on things.

Hope that helps explain,
Alex